The invention is based on a clutch device for an electric machine tool as and an electric machine tool.
Rotary hammers and chisel hammers can be used in a variety of operating modes. These types of operation are broken down into rotary drilling, e.g. when drilling into wood and steel, screw driving, stirring etc.; percussion drilling, e.g. when drilling into concrete, stone, etc.; and chiseling, e.g. when removing wall plaster or tiles and when producing openings in walls, etc.
The operating modes are usually produced by means of the mechanical transmission. Rotary drilling is characterized by the impact mechanism being deactivated while the spindle rotates. In percussion drilling, the impact mechanism is added to this spindle rotation. In chiseling mode, the spindle is disengaged from the rotary drive while the spindle is simultaneously locked in position (“spindle lock”).
Depending on the structural design of the transmission, an intermediate shaft is supported in stationary fashion by the housing or a flange and the switching occurs by means of components that are slid on the intermediate shaft. The intermediate shaft can also be comprised of several parts and the individual parts can be supported one inside the other so that the individual operating modes are produced by sliding the parts in the axial direction. This does enable a compact, short design, but requires all the forces of the impact mechanism and the torque to be introduced via the intermediate shaft and the bearing.
If the drive end bearing is supported directly in the housing, then it is possible to achieve a rugged, solid construction. This permits the intermediate shaft to then likewise be stationary and the switching to be achieved as described above. If the intermediate shaft is supported so that it can move in the axial direction, then this can be used to execute the switching, but results in a critical structural length and complicates placement of a customarily provided spur gear of the first transmission stage.